From 5d659bbb52a24f91cc6c0cf546ffcc0faa7e8f1a Mon Sep 17 00:00:00 2001 From: Sidhartha Kumar Date: Wed, 14 Aug 2024 12:19:31 -0400 Subject: maple_tree: introduce mas_wr_store_type() Introduce mas_wr_store_type() which will set the correct store type based on a walk of the tree. In mas_wr_node_store() the <= min_slots condition is changed to < as if new_end is = to mt_min_slots then there is not enough room. mas_prealloc_calc() is also introduced to abstract the calculation used to determine the number of nodes needed for a store operation. In this change a call to mas_reset() is removed in the error case of mas_prealloc(). This is only needed in the MA_STATE_REBALANCE case of mas_destroy(). We can move the call to mas_reset() directly to mas_destroy(). Also, add a test case to validate the order that we check the store type in is correct. This test models a vma expanding and then shrinking which is part of the boot process. Link: https://lkml.kernel.org/r/20240814161944.55347-5-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- tools/testing/radix-tree/maple.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'tools/testing/radix-tree/maple.c') diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index ef5b83cf94ea..ad42a36231fb 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -36283,6 +36283,38 @@ static void check_nomem_writer_race(struct maple_tree *mt) mtree_unlock(mt); } + /* test to simulate expanding a vma from [0x7fffffffe000, 0x7ffffffff000) + * to [0x7ffde4ca1000, 0x7ffffffff000) and then shrinking the vma to + * [0x7ffde4ca1000, 0x7ffde4ca2000) + */ +static inline int check_vma_modification(struct maple_tree *mt) +{ + MA_STATE(mas, mt, 0, 0); + + mtree_lock(mt); + /* vma with old start and old end */ + __mas_set_range(&mas, 0x7fffffffe000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, xa_mk_value(1), GFP_KERNEL); + mas_store_prealloc(&mas, xa_mk_value(1)); + + /* next write occurs partly in previous range [0, 0x7fffffffe000)*/ + mas_prev_range(&mas, 0); + /* expand vma to {0x7ffde4ca1000, 0x7ffffffff000) */ + __mas_set_range(&mas, 0x7ffde4ca1000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, xa_mk_value(1), GFP_KERNEL); + mas_store_prealloc(&mas, xa_mk_value(1)); + + /* shrink vma to [0x7ffde4ca1000, 7ffde4ca2000) */ + __mas_set_range(&mas, 0x7ffde4ca2000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, NULL, GFP_KERNEL); + mas_store_prealloc(&mas, NULL); + mt_dump(mt, mt_dump_hex); + + mas_destroy(&mas); + mtree_unlock(mt); + return 0; +} + void farmer_tests(void) { struct maple_node *node; @@ -36290,6 +36322,10 @@ void farmer_tests(void) mt_dump(&tree, mt_dump_dec); + mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | MT_FLAGS_USE_RCU); + check_vma_modification(&tree); + mtree_destroy(&tree); + tree.ma_root = xa_mk_value(0); mt_dump(&tree, mt_dump_dec); -- cgit